The invention relates to a collapsible container for transporting a liquid. In particular the invention relates to a container having a substantially rectangular base section, two opposite end sections and two opposite side sections. Each of the side and end sections are pivotally connected to one of the four sides of the base section. The collapsible container also has a top section pivotally connected to a side section or an end section, and a liner for storing the liquid The sections are arranged to pivot in relation to each other between a first position in which they in rows are extending mainly parallel across each other and a second position in which they jointly are defining a chamber for containing the liner.
The transport of liquid takes place to a great extent in transportable reusable receptacles that often are filled in one place and emptied at another. The emptied receptacles obviously weigh less than the full ones, but the space they occupy is the same when the containers are noncolapsable such as with steel tanks. These noncolapsable receptacles are therefore costly and difficult to return when they have to be filled again.
To deal with this problem, liquid containers have been devised that after emptying the container, it can then be made to assume a highly reduced volume. These containers each consist of a flexible liner in form of a large bag and a box with detachable walls for by means of fittings being assembled around the liner and support it on all sides. When the liner is empty, the box can be disassembled after which the loose walls can be stacked on top of each other and the liner laid flat. In the disassembled state, the container occupies relatively little space. However, the process of assembling and disassembling the box is time-consuming and difficult.
In order to facilitate this task, liquid containers have since been devised that are hinged on a pallet-like base frame.
When the liner has been emptied, the walls can then be collapsed in over the base frame quickly and easily, and when the liner is to be filled, the walls can be put up just as easily again to form a stable box around the liner. As the walls of this design can be swung in over the base frame, it is however very difficult for an assembler to put up the liner which typically has a threaded flange that is fastened in a base opening made in the base frame.
The object of the invention is to provide a container of the kind mentioned in the opening paragraph that is designed in such a way that the liner can be put up in the container more easily and quickly than currently known.
The novel and unique features according to the invention, which achieve this objective, is that the collapsible container has locking means such that in a second position locking the end sections and the side sections together in such a way that they only can be pivoted in over the base section. Furthermore, at least one of the end sections is constructed as a door section that consists partly of a frame connected pivotally about a swivelling axis to the base section and partly of at least one door connected pivotally about a second swivelling axis to the frame.
The locking means ensure that the container in the second position, that is in raised state, can resist the outwardly directed pressure of the liquid in a full liner. However, the special design of the door section still allows the door to be opened outwardly so that an assembler can easily and conveniently gain access to put up the liner.
The above locking means can advantageously consist of cooperating stops disposed on the end sections and the side sections, respectively. In this case, the stops of the end sections can be in form of a bolt with a shank and a head, and the stop of the side sections can be in form of a locking plate with a slot. These stops can be arranged in such a way that the shank of the bolt will be in the slot and its head behind the locking plate when the respective sections are in their second position. This allows the side sections and the ends to mutually secure each other against the pressure of the liquid in a full liner.
The stops on the end section can conveniently be arranged as a U fastened with the legs to the inside of the respective side section whereby the bottom of the U forms the locking plate with the slot.
In an especially simple and advantageous embodiment according to the invention, the frame of the door section can be shaped as an L with a first leg mounted pivotally about a horizontal swivelling axis on the base section and a second leg connected pivotally about a second swivelling axis to the door by means of hinges. At the same time, the stop of the door section can be disposed partly on the second leg of the L-shaped frame, partly on the lateral edge of the door opposite this second leg.
Having this structure, the door can be opened by at first swinging the entire door section at an appropriate angle inwardly about its horizontal swivelling axis. This results in a sufficient clearance to allow the door to subsequently be swung outwardly about the second swivelling axis and pass the corresponding stops on the side sections. When the frame of the door section subsequently is swung up again to upright position, the door can now be closed in a normal way by swinging about a horizontal swivelling axis.
When the side sections and the end sections are put up, they must be put in a position in which they are mainly perpendicular to the base section. The task of raising the container is facilitated when said position is locked by means of stops, mounted on the base frame and extending a distance up along the exterior of the respective sections.
As mentioned above, the end and side sections are locked together mutually in raised position by means of their cooperating stops. When the top section is pivotally fitted on the side section adjoining the second leg on the L-shaped frame of the door section, the top section can advantageously be locked together with both end and side sections. When the container is in the position of use, the sections thus lock one another together to an integrated unit that can resist the pressure of the liquid in a full liner.
When the end sections and the side sections are connected each pivotally about a horizontal swivelling axis to the base section, and the swivelling axis of the side sections is farther from the base frame than the swivelling axis of the end sections, the side sections will lie on top of the end sections when the container is collapsed. When the container is raised from this position, the side sections are consequently put up first after which the end sections are put up between the upright side sections.
The base section can advantageously be constructed as a pallet arranged to be lifted by a fork-lift truck. This pallet can furthermore have a bottom for supporting the full liner which typically has a threaded connecting piece led out through an opening in the container. When this opening is located under the door section, the assembler can, in the easiest way possible, assemble the threaded connecting piece of the liner via the door which can be opened in the way described above according to the invention.